This invention relates to the art of aircraft arresting systems and apparatus and, more particularly, to improved portable aircraft arresting apparatus.
Portable aircraft arresting equipment has been provided heretofore comprising a towable wheeled trailer carrying an energy absorber or brake unit and other equipment necessary to provide a self-contained unit for use in aircraft arresting systems. Such portable equipment selectively operable to provide a cable-type or a net-type arresting system is disclosed in co-pending U.S. patent application Ser. No. 581,807 filed Feb. 21, 1984 and assigned to the same assignee as the present application. The energy absorber or brake unit in such prior portable equipment has been comprised of a tape reel rotatable about a horizontal axis transverse to the opposite ends of the apparatus. The reel carries a tape having a free end extending laterally of the apparatus for attachment to a pendant or cable in connection with a cable-type arresting system or with the lower net strap of a stanchion supported net in connection with a net-type arresting system. In connection with the use of such portable systems, two of the towable units are positioned on opposite sides of an air strip with the tape ends of the two units aligned transversely of the runway, and the cable or lower net strip is attached to the ends of the tapes. Each trailer is ground supported with the trailer wheels elevated out of contact with ground, and the trailer is appropriately secured or anchored to the ground or to concrete anchors.
While such prior portable apparatus functions entirely satisfactorily with respect to arresting landing aircraft, there are limitations attendant to the structure and operation thereof which have rendered them unacceptable or incapable of use in certain situations. For example in this respect, the tape issue path in such previous units as mentioned above has been laterally outwardly of the frame or platform, whereby a considerable length of ground or other supporting surface is required along and parallel to the runway to accommodate the apparatus. While such deployment of the apparatus is desirable from the standpoint of minimizing use of runway width or of the ground surface adjacent to the runway, damage of the runway or the ground adjacent thereto can preclude such installation, or at least require extensive preliminary work which accordingly increases installation time and thus defeats one of the primary purposes for using portable equipment. In connection with the length of runway required to achieve aircraft arresting, damage to the runway or the ground adjacent thereto can make it extremely difficult to find a sufficient length of runway or ground on opposite sides of the landing path for the necessary longitudinal installation of the apparatus.
Another disadvantage resides in the fact that portable units heretofore were limited to the use of an energy absorber or brake unit in which the tape reel was rotatable about a horizontal axis transverse to the opposite ends of the trailer or frame. Thus, versatility and selectivity with respect to the brake unit was limited by the inability to employ energy absorber or brake units in which the tape reel was rotatable about a vertical axis. Such reel axis disposition provides a different tape orientation relative to the frame of the apparatus than that for the tape of a reel rotatable about a horizontal axis, and previous attempts to accommodate a brake unit having a tape reel rotatable about a vertical axis have resulted in detrimental dynamics in the arresting system during an arrestment operation.